17 



LIFE HISTORY OF THE BEETLE. 



The time of year when the investigation was made was especially 

 favorable for studying the hibernating habits of this insect, and 

 enabled the writer to commence a study of its life history with the 

 later part to the close of its dormant or inactive period. 



HOW IT PASSES THE FALL, WINTER, AND SPRING, 



The fall, winter, and spring, and part of the first summer month 

 are passed in all stages of the larva, from quite small to full grown, 

 as well as in the adult stage, developed the preceding summer or fall. 



So far as could be determined by the writer, the eggs deposited too 

 late in the fall to hatch before cold weather sets in, the pupae that 

 develop too late to change to the adult, and some of the very young 

 and tender adults, do not survive through the winter. 



The adults hibernate in the bark and usually but a short distance 

 from where they were located when they transformed from the pupae 

 or where the winter found them in their primary galleries. The 

 larvae are found in their mines, where they ceased feeding in the fall. 

 The very young to nearly matured larvae are often found in living- 

 bark, while the developed broods of the adults are nearly always in 

 bark which has recently died. In some trees many dead adults were 

 found, which, owing to some unfavorable condition, probably within 

 the bark itself, had died or been killed by the winter freezing, while 

 in the greater number of infested trees all stages but the eggs and 

 pupae, had not been injured in the least; indeed, they seemed to be in 

 as perfect health as when they ceased activity in the fall. 



WHEN ACTIVITY COMMENCES IN THE SPRING. 



When the first individuals were seen on May 28, near north latitude 

 45°, and at an altitude of about 2,000 feet, all of the hibernating stages 

 were inactive. This condition continued until about June 4, when 

 warmer weather set in and indications of activity were noted. On 

 June 5, at Hammel's Camp, on the Little Magalloway, the matured 

 larvae were found . to be almost ready to change to the pupae. The 

 next day, in the same locality, numerous pupae were observed, which 

 had just transformed from the larval stage. From that day on to 

 June 17 the pupae were commonly met with and the young larvae were 

 apparently feeding. Toward the 13th the adults showed evidence of 

 uneasiness, as if preparing to emerge, and the first one of the season 

 was observed excavating an entrance in the living bark of a healthy 

 spruce. I was not positive, however, that it had not commenced this 

 excavation last fall and remained in it over winter. Indeed none 

 were observed flying then or up to the time the last observations were 



3500— No. 28—01 2 



